Guidewire

ABSTRACT

Embodiments include a transition section for coupling a distal section and a proximal section of the guidewire. The transition section includes a main body having a first outer diameter; proximal and distal pin extensions having second and third outer diameters, wherein the proximal pin extension is configured to be fixed to the proximal section of the guidewire, and the distal pin extension is configured to be inserted into and fixed to the distal section of the guidewire. The distal pin extension includes a bore for receiving an inner core of the distal section of the guidewire. The first outer diameter may be greater than the second and third outer diameters. Also disclosed are methods of manufacturing a guidewire with such a transition section.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of U.S. patent applicationSer. No. 15/719,792 filed Sep. 29, 2017 (Allowed); which claims thebenefit of U.S. Provisional Application No. 62/402,852 filed Sep. 30,2016; the full disclosures which are incorporated herein by reference intheir entirety for all purposes.

BACKGROUND OF THE INVENTION

The invention relates to guidewires suitable for use in the deploymentof implants for lung volume reduction.

In chronic obstructive pulmonary disease, damage to tissue in certainparts of the lungs means that normal muscular inflation and deflation ofthe lungs becomes less efficient. One method to improve this situationis lung volume reduction, in which the diseased tissue is compressed orcollapsed so that the remaining tissue can behave more normally. In oneform of lung volume reduction, one or more elongate spring implants aredeployed into the airways in the diseased lung tissue and are allowed tocontract, gathering up the diseased tissue as they do so. Implants andsystems for such treatments are disclosed in WO 2007/106495 and WO2010/030993. In both cases, implants are deployed into the airways fromcatheter systems. The airways of the lungs are highly branched andtortuous, and lung tissue can be easily damaged. Therefore guidewiresare used to determine the path to the airway to be treated, the catheterfor delivery of the implant being advanced over the guidewire, which isthen removed so that the implant can be deployed through the properlypositioned catheter.

The guidewire must be capable of being pushed out of the catheter andinto airway, and rotated so that it advances in the desired direction,while at the same time being small enough that the delivery catheter canfit over it to be advanced into the lung for proper delivery of theimplant. In order to reduce the likelihood of kinking due to thecombination of compression and torsion, a composite structure has beenproposed for the guidewire, comprising an inner core extending throughan outer coil sheath. In order to allow the guidewire to be advancedthrough the catheter, the proximal part of the core is relativelythicker than the distal part, which is thinner to provide the necessaryflexibility to be directed through the airways without damaging the lungtissue. One result of this is that applying torque at the proximal endof the guidewire to steer the distal end in the required direction canresult in significant wind-up between the core and coil, making accuratecontrol of the distal end difficult.

The invention attempt to address the problem of how to provide moreaccurate control of the distal end while retaining the necessaryflexibility in the system.

SUMMARY

The various aspects of the present invention relate to improvedguidewires for use in deployment of lung volume reducing implants, suchas coils. One aspect provides a guidewire, comprising: an outer sheathhaving a proximal end and a distal end, and comprising a proximalsection, a transition section, and a distal section, wherein theproximal section extends from the proximal end of the outer sheath tothe transition section, and the distal section extends from thetransition section to the distal end of the outer sheath, and whereinthe distal section defines a bore extending from the transition sectionto the distal end of the outer sheath; and an inner core having aproximal end and a distal end, wherein the inner core extends throughthe bore of the distal section of the outer sheath, wherein the innercore is fixed to the outer sheath at the transition section, and whereinthe distal end of the inner core is fixed to the distal end of the outersheath at the distal end of the sheath.

By fixing the inner core to the outer sheath at the transition section,it is not necessary for the core to extend the whole length of thesheath and so allows different physical properties to be provided forthe proximal and distal sections of the sheath.

In one configuration, the proximal section of the outer sheath defines abore extending from the proximal end of the sheath to the transitionsection. In this case, the bore of the proximal section of the outersheath can be substantially unobstructed between the proximal end of thesheath and the transition section.

The proximal section of the outer sheath and the distal section of theouter sheath can comprise coils. In this case, the coil comprising theproximal section of the outer sheath can have different mechanicalproperties to the coil comprising the distal section of the outersheath. For example, the proximal section can be configured to applytorque to the transition section and distal section, and the distalsection can be configured for flexibility.

The transition section can comprise an adapter to which the coilscomprising the proximal and distal sections of the outer sheath arefixed. In one example, the transition section comprises a cylindricalbody having a proximal pin extension for insertion into and fixture toan open end of the coil comprising the proximal section of the outersheath, and a distal pin extension for insertion into and fixture to anopen end of the coil comprising the distal section of the outer sheath,the distal pin extension also comprising a bore for receiving and fixingthe inner core. This configuration allows a substantially constant outerdiameter across the transition section and so helps avoid snagging.

The proximal end of the inner core can be fixed to the outer sheath atthe transition section. The distal end of the outer sheath and thedistal end of the inner core can be fixed to a ball structure. Thus theend of the structure can have a atraumatic shape and so avoid damage tolung tissue as it is advanced.

The inner core can comprise a wire having a flattened portionintermediate the proximal and distal ends. The proximal and distal endsof the wire can have substantially the same diameter. This allowsmodification from a simple wire structure to provide a core thatpreferentially bends in one plane, assisting in directing the guidewirethough lung airways.

The outer sheath is dimensioned to pass through a catheter forintroduction into an airway of the lung of a patient.

The guidewire can further comprise an end fitting connected to theproximal end of the proximal section and configured to allow a user toapply torque to the proximal section. The end fitting can comprise a hubthat is permanently or removably connected to the proximal end of theproximal section.

Another aspect provides a system comprising a first catheter, aguidewire as defined above, and a second catheter, wherein the firstcatheter is configured for introduction into the major airways of thelung of a patient, the guidewire is configured to be advanced from alumen of the first catheter and further into a predetermined airway inthe lung of the patient, and the second catheter is configured to beadvanced through the lumen of the first catheter and over the guidewireinto the predetermined airway of the lung of the patient. The system canfurther comprise an implant configured for delivery through a lumen inthe second catheter and deployment into the predetermined airway of thelung of the patient.

Another aspect provides method of deploying a lung volume reductionimplant into a predetermined airway of a lung of a patient, comprisingadvancing the first catheter and the guidewire into a major airway ofthe lung; advancing the second catheter and guidewire through the lumenof the first catheter; advancing the guidewire from the lumen of thesecond catheter and directing the distal end of the guidewire furtherinto the predetermined airway by rotating the proximal end of the outersheath so as to point the distal end of the outer sheath in thedirection of the predetermined airway; withdrawing the guidewire fromthe second catheter; and advancing a lung volume reduction implantthrough the lumen of the second catheter and deploying the implant intothe predetermined airway.

Another aspect provides a system comprising: a first catheter configuredfor introduction into the major airways of the lung of a patient; asecond catheter configured to be advanceable through the lumen of thefirst catheter and further into a predetermined airway in the lung ofthe patient; and a guidewire according to any preceding aspects andconfigured to be advanced through a lumen of the second catheter andfurther into the predetermined airway, wherein the second catheter isconfigured to be further advancable over the guidewire and further intothe predetermined airway of the lung of the patient. The system canfurther comprise an implant configured for delivery through a lumen inthe second catheter and deployment into the predetermined airway of thelung of the patient.

Another aspect provides a method of deploying a lung volume reductionimplant into a predetermined airway of a lung of a patient, comprising:advancing the first catheter into a major airway of the lung; advancingthe second catheter and guidewire through the lumen of the firstcatheter so as to extend into a predetermined airway of the lung;further advancing the guidewire from the lumen of the second catheterand directing the distal end of the guidewire further into thepredetermined airway by rotating the proximal end of the outer sheath soas to point the distal end of the outer sheath in the direction of thepredetermined airway; further advancing the second catheter over theguidewire further into the predetermined airway; withdrawing theguidewire from the second catheter; and advancing a lung volumereduction implant through the lumen of the second catheter and deployingthe implant into the predetermined airway.

Other aspects of the invention will be apparent from the followingdescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 illustrate the human respiratory system:

FIG. 3 shows an example of a guidewire;

FIG. 4 shows further detail of the distal end of the outer sheath;

FIG. 5 shows further detail of the transition section;

FIG. 6 shows further detail of the distal end of the core;

FIG. 7 shows the distal sheath section, the core, and the transitionsection;

FIG. 8 shows further detail of the core;

FIG. 9 shows a system for placing a lung volume reduction implant;

FIGS. 10 and 11 show details of an implant;

FIG. 12 illustrates delivery of the implant;

FIG. 13 shows a fluoroscopic image of an implant in the positionillustrated in FIG. 12;

FIG. 14 shows a fluoroscopic image of an implant in a lung as thedelivery catheter is removed;

FIG. 15 illustrates the system after delivery of the implant.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 illustrate the human respiratory system, including thetrachea 12, which directs air from the nose 8 or mouth 9 into theprimary bronchus 16. Air enters the lung 20 from the primary bronchus16. As is shown in FIG. 2, the primary bronchus 16 branches into thesecondary bronchus 22, tertiary bronchus 24, bronchioles 26, terminalbronchioles 28, and finally into the alveoli 30.

FIGS. 3-8 illustrate various aspects of the guidewire. FIG. 3 shows aschematic view of an outer sheath of a guidewire, comprising a proximalsection 40, a transition section 42, and a distal section 44. Theproximal section 40 is formed of a spun coil which has a tight pitch andis substantially gapless. An example of such a coil is an HHS® (HelicalHollow Strand) Tube obtainable from Fort Wayne Metals of Fort Wayne,Ind., USA. A suitable tube can be formed from a single layer of 304VSpring Temper stainless steel filament(s) of approximately 0.029 cmthickness to give a coil tube of approximately 0.17 cm OD. The proximalsection 40 can have a bore that is substantially unobstructed so as togive substantially consistent torque transmission and bending capabilityalong its length. The distal section 44 is formed from a wound coil,such as 304V Spring Temper stainless steel wire of approximately 0.025cm thickness. A short section 46 near the distal end of the distalsection 44 is wound at a looser pitch so as to provide a highly flexibleregion as is shown in FIG. 4. The proximal and distal sections 40, 44are connected to each other by means of the transition section 42. FIG.5 shows the transition section 42 in more detail. The transition section42 comprises a substantially cylindrical main body 48 having proximaland distal extensions 50, 52 extending coaxially from opposite ends. Theextensions 50, 52 are of reduced OD compared to the OD of the main body48 and are sized to fit inside the respective bores of the proximal anddistal sections 40, 44. The OD of the main body 48 is substantially thesame as that of the proximal and distal sections 40, 44. The transitionsection can also be made from stainless steel and connected to theproximal and distal sections by welding. A deviation can be provided inthe transition section 42 so that the outer coil tube is naturally in aslightly bent configuration.

A hub 54 is affixed at the proximal end of the proximal section 40 bywhich a user can apply torque to the guidewire. The hub can bepermanently affixed, such as by gluing, or can be removable. A ball 56can be welded to the distal end of the distal section 44 to provide anatraumatic surface. The proximal section 40 can also include a markersection 58 to assist a user in determining the extend of insertion ofthe guidewire into a delivery system.

A core is provided inside the coil forming the distal section 44, asshown in FIGS. 6 and 7. The core is formed of a wire 60 that isconnected at one end in a bore 61 in the distal extension 52 of thetransition section 42, and at the other end is a bore in the ball 56.The wire 60 is substantially cylindrical at its ends, but has beenflattened to a thickness of about half of the original wire diameter ata position 62 close to the proximal end so that it will preferably bendin a direction perpendicular to the plane of the flattened section andassist in steering the end in use. As is shown in FIG. 8, a series ofmarkers 64 are positioned along the core between the transition section42 and the flattened section 62. The markers can be made of a materialvisible in a fluoroscopic imaging system, such as Pt/Ir.

In the configuration shown in these figures, distal section 44 isapproximately half as long as the proximal section. The overall lengthcan be of the order of 120 cm, although other lengths and ratios can beused according to requirements.

FIGS. 9-15 illustrate systems and methods using the guidewire describedabove.

The system of FIG. 9 comprises a bronchoscope including a bronchoscopecatheter 100 having a camera 102 at its distal end connected to a videoprocessing system 104. A delivery catheter 106 extends through the lumenof the bronchoscope catheter 100. The distal end 108 of the deliverycatheter 106 is provided with markers 110 visible to a fluoroscopicimaging system 112. A guidewire 114 of the type described above extendsthrough the lumen of the delivery catheter 106 and can be advanced outof the distal end 108. The end of the guidewire 114 also has markers 116(corresponding to markers 64 described above). A dilator 118 can beprovided to endure a smooth transition between the outer surface of theguidewire 114 and the outer surface of the delivery catheters 106.

The system of FIG. 9 is intended for use with an implant of the typeshown in FIGS. 10 and 11, although other shapes may also be used. In itsnormal state, the implant comprises an elongate member 120 that adopts acomplex shape 122 comprising a series of curved sections, each curvecentered on a separate axis. The implant 120 can be made from Nitinolwire and can have atraumatic terminals at the ends and one or morelength markers (not shown). For delivery, the implant 120 is distortedinto a relatively straight configuration 124 and constrained in adelivery cartridge 126.

In use, the bronchoscope catheter 100 of FIG. 9 is advanced into theupper airways of a patient either to the extent of its available length,or until its physical size prevents further insertion without damage tothe lung tissue. The delivery catheter 106, together with the guidewire114, is advanced through the lumen of the bronchoscope catheter and intothe airway. The guidewire 114 is then further advanced along thedelivery catheter 106 from the proximal end so as to extend from thedistal end 108 and project further into the airway. The mark 58 can bepositioned so as to indicate when the distal end of the guidewire 114 isat the distal end of the catheter 108. As the guidewire 114 is advancedfurther, it can be steered by applying a torque to the hub 54, thedeviation allowing the distal end to be pointed in a required directionand the flexible section 46 and flattened core section 62 allowing theend to be eased into the required airway on contact with the wall of theairway. Progress can be monitored either via the viewing field of thebronchoscope, or by use of the remote fluoroscopic imaging system 112once the end has passed out of this field of view. The deploymentcatheter 106 can be advanced with the guidewire 114 until its distal end118 is at or near the distal end of the guidewire 114 in the airway ofinterest.

The proximal section 40 is not configured to extend beyond the distalend 118 of the delivery catheter 106. Consequently, the proximal section40 can be configured for axial compression and torque transmission,together with the necessary degree of flexibility to be fed into thebronchoscope catheter 100. In the example described above, this isachieved using the tight pitch spun coil structure for the proximalsection 40. By avoiding the need for the core 60 to extend to the hub54, the proximal section 40 can be more flexible than the previouslyproposed structure and so provides for easier insertion into thecatheter 106. The marker 58 can be positioned so as to indicate that thedistal end of the guidewire 114 is at or near the distal end 118 of thedelivery catheter 106, indicating to the user that further progress mustbe monitored using one or other of the imaging systems 104, 112.

By providing an asymmetry in the guidewire construction, such as adeviation at the transition section 42, the distal end can be directedoff axis. This, together with the flexible region 46 and the flattenedportion 62 of the core 60 means that when the distal end reaches anairway junction 128, torque can be applied at the hub 54 to cause thedistal end to move radially in the airway, the flattened section 62providing for preferential bending in the plane perpendicular to theplane of the flattened section 62. The provision of the atraumatic ball58 and flexible end 46 mean that the airway tissue can provide areaction surface to allow control of the position without damage to thetissue.

Once the delivery catheter 106 is in position, it can be secured and theguidewire 114 withdrawn from the delivery catheter 106. The cartridge126 carrying the implant 120 can then be connected in its place, and theimplant 120 advanced along the delivery catheter 106 by a pusher devicehaving a detachable connector 130 as shown in FIG. 12. FIG. 13 showsremote imaging system view of the implant 120 at the end of the deliverycatheter 106. The implant 120 is held in place by the pusher device 130and the delivery catheter 106 is withdrawn, allowing the implant 120 toreturn to its as-manufactured shape (FIG. 14), reducing the volume oflung tissue in that region as it does so. Once the implant 120 iscompletely outside the delivery catheter 106, the connector 130 isdetached (FIG. 15) and the bronchoscope and delivery catheters 100, 106can be withdrawn from the lung.

Other variations are within the spirit of the present invention. Thus,while the invention is susceptible to various modifications andalternative constructions, certain illustrated embodiments thereof areshown in the drawings and have been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific form or forms disclosed, but on the contrary,the intention is to cover all modifications, alternative constructions,and equivalents falling within the spirit and scope of the invention, asdefined in the appended claims.

In the previous description, various embodiments of the presentinvention are described. For purposes of explanation, specificconfigurations and details are set forth in order to provide a thoroughunderstanding of the embodiments. However, it will also be apparent toone skilled in the art that the present invention may be practicedwithout the specific details. Furthermore, well-known features may beomitted or simplified in order not to obscure the embodiment beingdescribed.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening. Recitation of rangesof values herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate embodiments of the invention and does not pose a limitationon the scope of the invention unless otherwise claimed. No language inthe specification should be construed as indicating any non-claimedelement as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

What is claimed is:
 1. A transition section for coupling a distalsection and a proximal section of a guidewire, the transition sectioncomprising: a main body having a first outer diameter; a proximal pinextension having a second outer diameter, wherein the proximal pinextension extends proximally from the main body, and wherein theproximal pin extension is configured to be fixed to the proximal sectionof the guidewire; and a distal pin extension having a third outerdiameter, wherein the distal pin extension extends distally from themain body, and wherein the distal pin extension is configured to beinserted into and fixed to the distal section of the guidewire, thedistal pin extension comprising a bore for receiving an inner core ofthe distal section of the guidewire; wherein the first outer diameter isgreater than the second and third outer diameters.
 2. The transitionsection of claim 1, wherein the proximal section of the guidewirecomprises a coil, and wherein the proximal pin extension is configuredto be fixed to an open end of the coil.
 3. The transition section ofclaim 1, wherein the distal section of the guidewire comprises a coil,and wherein the distal pin extension is configured to be fixed to anopen end of the coil.
 4. The transition section of claim 1, wherein theproximal section of the guidewire comprises a first coil and the distalsection of the guidewire comprises a second coil.
 5. The transitionsection of claim 1, wherein the second outer diameter and the thirdouter diameter are substantially same.
 6. The transition section ofclaim 1, wherein the first outer diameter is substantially same as anouter diameter of the distal section of the guidewire and an outerdiameter of the proximal section of the guidewire.
 7. The transitionsection of claim 1, wherein the proximal pin extension and the distalpin extension extend coaxially from opposite ends of the main body. 8.The transition section of claim 7, wherein the proximal pin extensionand the distal pin extension are cylindrical.
 9. The transition sectionof claim 8, wherein the main body is cylindrical.
 10. The transitionsection of claim 1, wherein the transition section is welded to theproximal section of the guidewire and the distal section of theguidewire.
 11. The transition section of claim 10, wherein thetransition section comprises a steel material.
 12. The transitionsection of claim 1, wherein the transition section is dimensioned topass through a catheter for introduction into an airway of a lung of apatient.
 13. The transition section of claim 1, wherein the main body iscylindrical.
 14. A method of manufacturing a guidewire with a distalsection and a proximal section coupled together, the method comprising:disposing a proximal pin extension of a transition section according toclaim 1 within a bore of the proximal section of the guidewire, whereinthe proximal pin extension extends from a main body of the transitionsection according to claim 1; disposing ng a distal pin extension of thetransition section according to claim 1 within a bore of the distalsection of the guidewire, wherein the distal pin extension extends fromthe main body of the transition section according to claim 1; fixing thetransition section according to claim 1 to the proximal section of theguidewire and the distal section of the guidewire; and fixing an innercore of the distal section of the guidewire within a bore of the distalpin extension, wherein the inner core comprises a wire that extendsthrough the distal section of the guidewire.
 15. The method of claim 14,further comprising fixing a ball structure at a distal end of theguidewire.
 16. The method of claim 15, wherein fixing the ball structureat the distal end of the guidewire comprises disposing the inner core ofthe distal section of the guidewire within a bore of the ball structure.17. The method of claim 15, wherein fixing the ball structure at thedistal end of the guidewire comprises welding the ball structure to thedistal end of the distal section of the guidewire.
 18. The method ofclaim 14, further comprising flattening a segment at a distal portion ofthe inner core, wherein the flattened segment is configured to assist insteering a distal tip of the guidewire.
 19. The method of claim 18,further comprising disposing one or more markers between the transitionsection according to claim 1 and the flattened segment of the innercore, wherein the markers allow for remote monitoring by an imagingsystem.
 20. The method of claim 14, further comprising welding thetransition section according to claim 1 to a portion of the proximalsection of the guidewire and a portion of the distal section of theguidewire.
 21. The method of claim 14, further comprising forming thedistal section of the guidewire from a wound coil, wherein a distalregion of the distal section is wound at a looser pitch than a proximalregion of the distal section, so as to provide flexibility at the distalregion.